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5. Aircraft noise characteristics
5.1 Noise propagation, brief reminder
Land transport noise sources (railways, roads) are linear, and noise decay as a function of distance is in principle "cylindrical", although shielding effects are possible. Airborne noise is 3D and, in free field conditions, its attenuation as a function of distance comprises two terms:
geometric, spherical attenuation: L = L 0 – 20log(d/d 0 ), which corresponds to a decrease of 6 dB per doubling of distance;
atmospheric absorption, which depends on frequency; negligible at low frequencies, it can be very significant at high frequencies, such as engine noise.
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Aircraft noise characteristics
Monitoring engineering: long-term management
Bibliography
Software tools
INM Integrated Noise Model 7.0 Ground noise modeling and mapping software. Published by the Federal Aviation Administration, USA. The software is now used by most countries worldwide.
Directory
Bruel & Kjaer : http://www.bksv.fr/
Norsonic : http://www.norsonic.com
Topsonic : http://www.topsystem.de
Events
INTER-NOISE : http://www.internoise2014.org/
French Acoustics Congress (CFA) : http://cfa2014.conference.univ-poitiers.fr/
Standards and norms
- Acoustics – Unattended monitoring of aircraft sound in the vicinity of airports. - ISO/CD 20906 - 2009
- Acoustics – Description, assessment and measurement of environmental noise. - ISO/DIS 1996-2.2 - 2005
- Uncertainty of measurement – Part 3: Guide to the expression of uncertainty in measurement (GUM : 1995) - ISO/IEC Guide 98-3 - 2008
- Acoustics – Procedure for describing aircraft noise heard...
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